Liner hanger running tools have been used for decades to run liner hangers into a well. The prior art liner hanger running tools are disclosed in U.S. Pat. Nos. 4,583,593 and 4,603,543, and Publication 2004/0194954A1.
One of the significant problems with running a liner hanger in a well concerns the high loads conventionally applied at the surface to push, pull, rotate and/or drill the liner in place. These high loads are in part due to the liner compressing fluids in the well during a liner run-in operation. Fluid bypass between the liner and the casing is typically quite limited.
A tool was manufactured and sold for use in a tar application, wherein the tool had an internal fluid bypass to aid in getting the liner to the desired depth in the wellbore. The internal bypass in the running tool allowed the fluid to flow upward through the inside of the liner and through the bypass in the running tool, and then exit above the liner. The liner running tool was attached to a liner running adapter by a c-ring. When the liner was run to the releasing depth, the mechanical running tool was rotated to the right to shear a set of pins, so that continued right hand rotation would move a releasing sleeve up to release a c-ring from the running adapter. Both right hand rotation and torque to the liner are limited in this tool by the shear pin releasing concept.
The disadvantages of the prior art are overcome by the present invention, and an improved liner hanger running tool and method of operating such a tool are hereinafter disclosed.